Stabilized vinyl polymer



Patented Sept. 21, 1943 STABILIZED VINYL POLYMER Leo J. Stage, Roselle Park, and Mortimer T. Harvey, East Orange, N. 1., assignors to Harvel Research Corporation, a corporation of New Jersey No Drawing.

Application May 31, 1941, Serial No. 396,164

4 Claims. (01. 260-86) The present invention relates to compositions of matter in which a plasticised polyvinyl chloride has incorporated with it a color stabilizer v which serves to keep the polyvinyl chloride from changing color or darkening when it is subjected to heating such as in the hot plastic milland in hot extrusion dies. Y

The various polyvinyl esters which are comprised entirely, or partly of polyvinyl chloride are found to break down sufllciently turn then to a reddish brown color when subjected to heat such as is met or developed in the regular mixing apparatus and in extruding dies. We have found that a small percentage of a tertiary-amyl urea mixed in with the vinyl ester and its plasticiser will prevent this discoloration. r

Example 1.-A composition mixed on the hot rubber mill was composed, as fbllows: 450 grams (as color. stabilizer) were mixed and compounded on hot plastic mill.

The amount of stabilizer used is about 2% of the polyvinyl ester used, and this stabilizer was found to be efficient for stabilizing the color of 75 grams di-2-ethylhexyl phthalate and 9 grams of the stabilizer of Example 4 (lauric acid-tertiary butyl urea reaction product) were compounded of Vinylite VYNW (interpolymer of 95% vinyl chloride and 5% vinyl acetate), 150 grams tricresyl phosphate, 75 grams di 2 etl'ylhexvl I phthalate and 27 grams tertiary amyl urea.

The tertiary amyl urea, used as color stabilizer, represents 5.94% by weight of the vinyl polymer.

The tertiary amyl urea showed definite stabilizing efiect, without it the same vinylite-plasticiser turns reddish brown when milled on a hot plastics mill. The reddish brown color developed Example 4.-A small amount of surface sub- I limation was noted in some milled batches on standing at room temperature. To overcome this sublimation the following stabilizer was prepared.

Heat 1 gram mole weight of lauric acid to '70" C. and add and stir in 1 gram mole weight of tertiary butyl urea and allow batch to cool to room temperature, (200.3 g. lauric acid and 116.6 8. tertiary butyl urea). v r

450 grams of Vinylite VYNW," 225 grams of tricresyl phosphate and 9 grams of the reaction ,product of lauric acid and tertiary butyl urea with heat and iron metal contactis a sign of on hot mill.

Example 6.450 grams of "Vinylite VYNW, 150 grams of di-2-ethylhexyl phthalate, '75 grams oftricresyl phosphate .and 9 grams of stabilizer I of Example 4 (lauric acid-tertiary butyl urea reaction product) were compounded on hot mill.

In an experimental way factory size batches en in the illustrative. examples it is to beunderstood that the color stabilizer of the present invention is effective on polyvinyl chlorides generally and more particularly on polyvinyl chlorides running from 100% vinyl chloride content down to 5% vinyl chloride content, for example, in copolymers of vinyl chloride and vinyl acetates the vinyl chloride content can be from to 5% and the vinyl acetate can be from 5% to And in the use of the fatty acid for preventing blooming the fatty acid-can be used in amounts from one one-hundredth of a molecular equivalent to one molecular equivalent with respect to the amount of tertiary alkyl urea used- Illus-- trative examples of fatty acids suitable for this -,,and palmitic.

use are lauric acid, stearic. aci acid.

Having thus described our invention, what we claim and desire to protect by Letters Patent is: 1. A thermoplastic composition of matter comprising a polyvinyl chloride, a plasticizer therefor and alcolor stabilizer comprising a reaction product of a tertiary alkyl urea and a saturated fatty acid having 12 to 18 carbon atoms in the molecule.

,2. In combination with a thermoplastic poly-- I vinyl chloride, 9. color's'tabilizing agent for said polyvinyl chloride comprising the reaction prodnot of a saturated" fatty acid having 12 toalfl. carbon atoms in themolecule and a tertiary aliryl urea having from four to six carbon atoms in the tertiary alkyl group.

3. In combination with a thermoplastic polyvinyl chloride, a color stabilizing agent for said polyvinyl chloride comprising the reaction prodnot of a tertiary alkyl urea having from four to six carbon atoms in the tertiary alkyl group and from one one-hundredth of a molecular equivalent to one molecular equivalent of a saturated fatty acid having 12 to 18 carbon atoms in the 10 moleculei 4. A thermoplastic composition of matter comprising a polymer selected from the group consisting of polyvinyl chloride and copolymer of vinyl chloride and vinyl acetate, a plasticizer therefor, and a color stabilizer comprising a reaction product of tertiary alkyl urea having from four to six carbon atoms in the tertiary alkyl group and a saturated fatty acid having twelve to eighteen carbon atoms in the molecule.-

LEO J. STAGE. MORTIMER '1. HARVEY. 

